from django import forms
from django.conf.urls import url
from django.contrib import messages
from django.contrib.messages.views import SuccessMessageMixin
from django.http import HttpResponse, HttpResponseRedirect
from django.template import engines
from django.template.response import TemplateResponse
from django.urls import reverse
from django.views.decorators.cache import never_cache
from django.views.generic.edit import FormView


TEMPLATE = """{% if messages %}
<ul class="messages">
    {% for message in messages %}
    <li{% if message.tags %} class="{{ message.tags }}"{% endif %}>
        {{ message }}
    </li>
    {% endfor %}
</ul>
{% endif %}
"""


@never_cache
def add(request, message_type):
    # Don't default to False here to test that it defaults to False if
    # unspecified.
    fail_silently = request.POST.get('fail_silently', None)
    for msg in request.POST.getlist('messages'):
        if fail_silently is not None:
            getattr(messages, message_type)(request, msg, fail_silently=fail_silently)
        else:
            getattr(messages, message_type)(request, msg)
    return HttpResponseRedirect(reverse('show_message'))


@never_cache
def add_template_response(request, message_type):
    for msg in request.POST.getlist('messages'):
        getattr(messages, message_type)(request, msg)
    return HttpResponseRedirect(reverse('show_template_response'))


@never_cache
def show(request):
    template = engines['django'].from_string(TEMPLATE)
    return HttpResponse(template.render(request=request))


@never_cache
def show_template_response(request):
    template = engines['django'].from_string(TEMPLATE)
    return TemplateResponse(request, template)


class ContactForm(forms.Form):
    name = forms.CharField(required=True)
    slug = forms.SlugField(required=True)


class ContactFormViewWithMsg(SuccessMessageMixin, FormView):
    form_class = ContactForm
    success_url = show
    success_message = "%(name)s was created successfully"


urlpatterns = [
    url('^add/(debug|info|success|warning|error)/$', add, name='add_message'),
    url('^add/msg/$', ContactFormViewWithMsg.as_view(), name='add_success_msg'),
    url('^show/$', show, name='show_message'),
    url('^template_response/add/(debug|info|success|warning|error)/$',
        add_template_response, name='add_template_response'),
    url('^template_response/show/$', show_template_response, name='show_template_response'),
]